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/*
 * Copyright 2013 serso aka se.solovyev
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Contact details
 *
 * Email: [email protected]
 * Site:  http://se.solovyev.org
 */

package org.solovyev.android.view.drag;

import android.content.Context;
import android.graphics.Canvas;
import android.os.Handler;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import org.solovyev.android.view.AndroidViewUtils;
import org.solovyev.common.math.Point2d;
import org.solovyev.common.text.Strings;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

public class DragButton extends Button {

	@Nullable
	private Point2d startPoint = null;

	@Nullable
	private org.solovyev.android.view.drag.OnDragListener onDragListener;

	@Nonnull
	private DragButton.OnTouchListenerImpl onTouchListener;

	private boolean showText = true;

	@Nonnull
	private final Handler uiHandler = new Handler();

	@Nullable
	private CharSequence textBackup;

	public DragButton(@Nonnull Context context, @Nonnull AttributeSet attrs) {
		super(context, attrs);
		setOnTouchListener(new OnTouchListenerImpl());
	}

	public DragButton(@Nonnull Context context, @Nonnull DragButtonDef dragButtonDef) {
		super(context);

		setOnTouchListener(new OnTouchListenerImpl());

		setText(dragButtonDef.getText());
	}

	public void setOnDragListener(@Nullable org.solovyev.android.view.drag.OnDragListener onDragListener) {
		this.onDragListener = onDragListener;
	}

	@Nullable
	public org.solovyev.android.view.drag.OnDragListener getOnDragListener() {
		return onDragListener;
	}

	public void applyDef(@Nonnull DragButtonDef buttonDef) {
		AndroidViewUtils.applyButtonDef(this, buttonDef);
	}

	@Override
	public void setOnTouchListener(OnTouchListener l) {
		if (l instanceof OnTouchListenerImpl) {
			this.onTouchListener = (OnTouchListenerImpl) l;
			super.setOnTouchListener(l);
		} else {
			this.onTouchListener.nestedOnTouchListener = l;
		}
	}

	/**
	 * OnTouchListener implementation that fires onDrag()
	 *
	 * @author serso
	 */
	private final class OnTouchListenerImpl implements OnTouchListener {

		@Nullable
		private OnTouchListener nestedOnTouchListener;

		@Override
		public boolean onTouch(@Nonnull View v, @Nonnull MotionEvent event) {
			// processing on touch event

			boolean consumed = false;

			// in order to avoid possible NPEs
			final Point2d localStartPoint = startPoint;
			final org.solovyev.android.view.drag.OnDragListener localOnDragListener = onDragListener;

			if (localOnDragListener != null) {
				// only if onDrag() listener specified

				Log.d(String.valueOf(getId()), "onTouch() for: " + getId() + " . Motion event: " + event);

				switch (event.getAction()) {
					case MotionEvent.ACTION_DOWN:
						// start tracking: set start point
						startPoint = new Point2d(event.getX(), event.getY());
						break;

					case MotionEvent.ACTION_UP:
						// stop tracking

						if (localStartPoint != null) {
							consumed = localOnDragListener.onDrag(DragButton.this, new DragEvent(localStartPoint, event));

							if (consumed) {
								if (localOnDragListener.isSuppressOnClickEvent()) {
									// prevent on click action
									v.setPressed(false);
								}
							}
						}

						startPoint = null;
						break;
				}
			}

			if (nestedOnTouchListener != null && !consumed) {
				return nestedOnTouchListener.onTouch(v, event);
			} else {
				return consumed;
			}
		}
	}

	@Override
	protected void onDraw(Canvas canvas) {
		CharSequence text = getText();
		if (!Strings.isEmpty(text)) {
			super.onDraw(canvas);
		} else {
			if (!AndroidViewUtils.drawDrawables(canvas, this)) {
				super.onDraw(canvas);
			}
		}
	}


	public boolean isShowText() {
		return showText;
	}

	public void setShowText(boolean showText) {
		if (this.showText != showText) {
			if (showText) {
				setText(textBackup);
				textBackup = null;
			} else {
				textBackup = this.getText();
				setText(null);
			}
			this.showText = showText;
		}
	}
}